This invention relates to tape, and more particularly, to tamper-evident, self-adhesive resealable tape for packages or containers such as bags, pouches and the like. The tape of the present invention contains a printed pattern. When the tape is peeled apart, the printed pattern is broken and readily indicates that the container has been opened. This provides a warning that the contents of the container may have been tampered with or removed even if the tape is subsequently resealed to secure the container.
Package security is a major concern of purveyors, shippers, and consumers of all types of products. Packages are frequently opened and their contents removed while in transit, in storage, or even on the store shelf. Packages whose security has been violated are often resealed to avoid suspicion and remove any outward evidence of tampering or pilferage. In consequence, it is difficult to determine where in the chain of distribution the theft or tampering occurred. Tamper-evident tapes enable manufacturers, shippers, and retailers to determine where the breach occurred and take appropriate measures to root out the person or persons responsible. Tamper-evident tape is also valued by consumers of food stuffs or other products wrapped in bags or pouches for it provides assurance that the product was not opened or adulterated prior to purchase.
Containers such as bags and pouches have been made with tamper-evident closures for many years. For example, the banking industry has long used bags or pouches containing a pressure-sensitive adhesive located on one side of the opening of the bag for shipping currency or other valuable items. To close the bag, a peel-back strip covering the free side of the adhesive is removed, and the exposed surface of the adhesive is then pressed against the opposite side of the bag. If a bag of this type is opened, the pressure-sensitive adhesive will distort and break apart, and thereby indicate that the bag has been opened. Bags of this type are large, bulky, and expensive to manufacture. They are therefore inappropriate for shipping consumer products such as food, electronic parts, or pharmaceutical items, and are unsuitable for consumer use in the home.
Another common tamper-evident closure used with cardboard or paper packages, such as boxes and envelopes, is in the form of a tape or label that is applied directly to the package. This type of tape or label has one appearance when applied to the package, and takes on a second, different and distinct appearance when it is removed. If the tape is reapplied to the package, it retains the second appearance. Tapes of this type are generally used to seal the flaps of boxes or cartons by applying the tape directly to the flaps to hold them in place and thereby secure the contents from tampering or removal.
Typically, this kind of tape displays a trademark or logo, or other information such as "This Side Up" or "Fragile," when first applied to the container. When the tape is removed from the container to gain access to its contents, the tape leaves behind some indication, such as the words "Void" or "Opened," to indicate that the container has been opened. This message remains on the container even when the tape is reapplied and prevents the tape from obscuring the revealed indication. Tapes of this kind are commonly used on containers such as boxes or cartons and must be applied directly to the container (e.g., over a flap or opening) in order to be most effective. Tapes of this sort would be undesirable for containers that need to be resealed such as bags or pouches because such containers preferably require a self-adhesive closure that can be reapplied (i.e., resealed) if necessary.
Furthermore, currently available tamper-evident tape is provided in long lengths in the form of a roll so that it may be applied automatically by machine. Such tapes necessarily include, however, a sheet of lining material that is interposed between and separates the adhesive coating from the underlying exposed surface of the tape to prevent the two from sticking together when the tape is provided in the form of a roll. The liner must be removed from the tape and discarded before the tape is applied to the container. A liner thus creates more work for the user and decreases efficiency. It is also more difficult and expensive to use automatic equipment to apply tape containing a liner.
It is therefore an object of the present invention to provide a self-wound, self-adhesive, resealable tamper-evident tape for containers such as bags or pouches.